682 
BULLETIN OF THE BUREAU OF FISHERIES 
Sable in some summers enters the gulf about as warm as is the contribution from 
the Cape Sable dead water (p. 835) ; actually warmer than the water with which it 
mixes in the offing of Cape Sable or close by to the westward. Although icy cold 
water persists on bottom right through the summer only a few miles east of the 
cape, we have no evidence that anything from this source actually penetrates the 
gulf after May. 
In short, the Nova Scotian current acts as a chilling agent in the Gulf of Maine 
for only a few weeks during the spring, and then more to retard vernal warming 
(p. 558) than actually to lower the temperature of the part of the gulf into which it 
debouches below the readings prevailing there before the current commences to 
flood past Cape Sable. During the short period of its westward flood, however, 
and for some weeks thereafter, its chilling influence on the eastern side of the gulf is 
obvious enough, as is described in the account of the distribution of temperature in 
the spring (p. 553). 
We have next to consider how far the difference in temperature between the 
side of the gulf most directly exposed to the effects of the Nova Scotian current and 
the opposite side most remote from it is recognizable at other seasons of the year. 
This problem is complicated by regional differences in the activity of vertical 
stirring by the tides, reflected in lower and lower surface temperatures at successive 
stations around the shore line of the gulf from Massachusetts Bay to Nova Scotia, 
but higher and higher temperatures at the 50 to 100 meter stratum. In order to 
be instructive for the water mass as a whole, regional comparison must therefore be 
based on a calculation of the mean temperature of the entire column. To name 
one part of the gulf as potentially colder than another, or vice versa, on the 
evidence of temperature of any one given level can only prove misleading. 
In calculating the mean temperature the gulf is best divided into two sub- 
divisions — (1) the basin outside the 100-meter contour and (2) the shoaler water of 
the coastwise zone. 
An earlier report (Bigelow, 1915) gives calculations of the mean temperature of 
the stratum inclosed between the surface and the 50-fathom level for the basin, 
which would apply closely enough to the upper 100 meters. 
Appi oximate mean temperature ( °C .) for the upper 50 fathoms, or 100 meters, of the basin, August, 
1913 
Locality 
Station 
Mean 
tempera- 
ture 
Locality 
Station 
Mean 
tempera 
ture 
10087 
7.9 
Off Penobscot Bay 
10091 
10.0 
10086 
9.7 
Near Cashes Ledge 
10090 
8.6 
10105 
8.3 
Near central part of basin 
10092 
8.0 
10104 
8. 4 
Off Mount Desert __ 
10100 
9. 1 
10103 
9. 1 
10097 
10.2 
10089 
8.3 
Near Lurcher Shoal 
10096 
10. 1 
10102 
9.2 
East side of basin 
10093 
10.0 
10101 
9. 4 
Do __ 
10094 
8.4 
According to this table the eastern side of the basin, with the waters along 
the Nova Scotian slope and off the mouth of the Bay of Fundy, was potentially 
the warmest part of the gulf (10°), not the coldest, as the popular belief that an 
